Mizokami K, Fukuhara M, Nohmi T, Sunouchi M, Fujimori K, Takanaka A, Omori Y
Department of Pharmacology, National Institute of Hygienic Sciences, Tokyo, Japan.
Drug Metab Dispos. 1988 Jan-Feb;16(1):151-5.
Characteristics of mixed-function oxidases in the liver of house musk shrew, Suncus murinus, were studied. The basal level of cytochrome P-450 and the activity of drug-metabolizing enzyme in hepatic microsomes of Suncus murinus is relatively lower than that of rats, while the level of cytochrome b5 and NADPH-cytochrome c reductase is approximately the same as that of rats. The treatment of Suncus murinus with phenobarbital and 3-methylcholanthrene elevated the level of cytochrome P-450 and the activity of drug-metabolizing enzymes, but not the level of cytochrome b5. Two distinct forms of cytochrome P-450 have been purified from hepatic microsomes of 3-methylcholanthrene-treated Suncus murinus. These forms have their absorption maximum at 448.0 nm and 448.5 nm in CO-bound reduced form, and one is in the high-spin state and the other is in the low-spin state. They are different in their molecular weights (53,500 and 55,000) and in their spectral and catalytic properties. Characteristics of these forms were compared with those of the major forms of cytochrome P-450 purified from livers of rats treated with 3-methylcholanthrene.
研究了家麝鼩肝脏中混合功能氧化酶的特性。家麝鼩肝微粒体中细胞色素P-450的基础水平和药物代谢酶的活性相对低于大鼠，而细胞色素b5和NADPH-细胞色素c还原酶的水平与大鼠大致相同。用苯巴比妥和3-甲基胆蒽处理家麝鼩可提高细胞色素P-450的水平和药物代谢酶的活性，但不能提高细胞色素b5的水平。已从用3-甲基胆蒽处理的家麝鼩肝微粒体中纯化出两种不同形式的细胞色素P-450。这些形式在CO结合还原形式下的最大吸收波长分别为448.0nm和448.5nm，一种处于高自旋状态，另一种处于低自旋状态。它们的分子量（53,500和55,000）以及光谱和催化特性都不同。将这些形式的特性与从用3-甲基胆蒽处理的大鼠肝脏中纯化出的细胞色素P-450主要形式的特性进行了比较。
